Analysis of the management of the sardine crisis Sardinella aurita in Venezuela and commentary on fishing gears and statistics

Abstract

The sardine Sardinella aurita, fished since 1927, is Venezuela's most significant fishery resource. The national catch reached a record high of 200,000 tons in 2004 but diminished nationally by 50% in 2005 and by 90% on Margarita Island, marking the beginning of a crisis in sardine fishing. Based on indicators of overexploitation, the fishing authority increased the minimum size required for
capture and prohibited fishing for three months in 2013. The validity of these measures is studied here. A reduction in size may indicate intensive exploitation, and thus, the records of 28,217 sardines measured between 2002 and 2016 in the southeast region of Margarita Island were examined. Prior to the crisis, in 2003 and 2004, the average size was 195.48 and 196.95 mm in total length (TL), respectively. With the onset of the crisis (2005), the size was 201.95 mm, surpassing the measurements obtained in the other years of the period studied (181.27 to 191.89 mm). The conclusion was drawn that no great change was identifiable in the annual average size, providing no support
for the supposed overexploitation. The 20 cm TL value reported by certain studies for the average length at maturity (Lm50%) is discussed in relation to the increase in the minimum size of capture to 19 cm and considered to be flawed by biased sampling. Moreover, the sardine
stock would already have been exhausted were the Lm50% value of 20 cm accurate because for decades, the average size of capture had been < 20 cm. The true Lm50% of S. aurita is < 17 cm, as in the eastern Atlantic Ocean (African waters and the Mediterranean Sea). Furthermore, the prohibition of fishing from January-March is not warranted because the ban occurs during months when sardine eggs
show relatively low abundance in the plankton. Fishing gear and statistics are also discussed. This study leads to the recommendations that management measures be reconsidered and that the consequences of fishing with equipment known as the "machine" be investigated.